The present invention relates to a drain cleaning apparatus and, more particularly, to a drain cleaning apparatus having a remotely adjustable feed control for controlling the feeding of a drain cleaning cable.
One type of common prior art drain cleaning apparatus in wide use today comprises a cable drum that carries a conventional drain cleaning cable mounted on a wheeled cart or stationary frame. The cable drum is mounted such that it may be rotated relative to the wheeled cart or frame by a motor provided therewith. The drain cleaning cable is conventionally an elongate, flexible member made of tightly wound spring wire and is wound about the central axis of the cable drum and is thus rotatable with the cable drum. The free or outer end of the drain cleaning cable is adapted to be pulled from the cable drum for use in cleaning a drain and pushed back into the cable drum for storage during periods of non-use.
It is known in the art that a rotating cylindrical member, such as a drain cleaning cable, can be advanced by using a plurality of rollers that engage the cylindrical member. Typically, the rollers are mounted on a frame or housing that has an opening with an axis that aligns with the central axis of the cylindrical member to be advanced. In some prior art devices, the rollers have rotational axes that are simultaneously variable to control the direction of advancement of the rotating cylindrical member.
Such rollers have been used in prior art drain cleaning apparatuses to advance or feed a drain cleaning cable both in and out of a rotating cable drum. One such prior art drain cleaning apparatus is described in Salecker et al., U.S. Pat. No. 5,507,062, the disclosure of which is incorporated herein by reference.
FIGS. 1 and 2 show the drain cleaning apparatus described in Salecker et al., which includes a cable drum 12 mounted on a wheeled cart 14. The cable drum 12 carries a drain cleaning cable 16 and is mounted for rotation by a motor 18 relative to the wheeled cart 14. A mechanism for advancing the drain cleaning cable 16 is shown generally at 10. The mechanism 10 has a frame 20 defining an opening 22 through which the drain cleaning cable 16 is directed for advancement thereof in a line substantially parallel to the length of the drain cleaning cable 16. The mechanism 10 has a rigid bracket 23 that is fixedly mounted upon an upright support 24 on the cart so that the rotational axis of the cable drum 12 coincides with the central axis 26 of the frame opening 22. Advancing rollers 28, 30 and 32 project into the frame opening 22 and have peripheral surfaces 34, 36, and 38 which cooperatively define an effective diameter for receipt of the drain cleaning cable 16.
The rollers 28, 30 and 32 rotate relative to the frame 20 about spaced axes 40, 42, and 44, respectively. With the axes 40, 42 and 44 parallel to the central axis 26 of the frame opening 22, the device is in neutral position. That is, the drain cleaning cable 16 being rotated by the cable drum 12 effects rotation of the rollers 28, 30 and 32 without the drain cleaning cable 16 being withdrawn into the cable drum 12 or advanced therefrom. Through a control arm 46, the axes 40, 42 and 44 of the rollers 28, 30 and 32 can be reoriented. With the control arm 46 moved to a forward advance position, shown in FIG. 2, the roller axis 40, 42 and 44 are uniformly angled relative to the frame opening axis 26 to thereby define a helical engagement path which results in the advancement of the drain cleaning cable forwardly out of the cable drum 12. Pivoting of the control arm 46 through approximately 90xc2x0, in a counter-clockwise direction in FIG. 2, places the advancing mechanism 10 in a reverse mode position. In this mode, the axes 40, 42 and 44 are simultaneously repositioned through approximately 90xc2x0 from the position they occupied with the control arm 46 in the forward position. This results in the advancement or feeding of the drain cleaning cable 16 in a reverse direction, i.e., back into the cable drum 12.
One drawback of the drain cleaning apparatus described in Salecker et al. is that in order to adjust the operation of the mechanism 10 among the neutral, forward advancing, and reverse advancing positions, the user must be in proximity with the mechanism 10 so as to have access to the control arm 46. When cleaning a drain, it is often not possible to move the drain cleaning apparatus comprising the cable drum 12 and wheeled cart 14 close to the opening of the drain due to, for example, some obstruction. In such a case, the user must take out a substantial length of drain cleaning cable 16 to reach the work area surrounding the opening to the drain. Because in such a case the work area is a distance away from the mechanism 10, the user cannot readily reach the control arm 46 to adjust the drain cleaning apparatus among the various operating positions.
Another prior art drain cleaning apparatus is described in Rutkowski, U.S. Pat. No. 6,009,588. The drain cleaning apparatus described in Rutkowski includes a rotatable motor driven cable drum carrying a drain cleaning cable that is mounted on a frame. Rutkowski describes a manually operable cable feed device that facilitates the selective feeding of the drain cleaning cable outwardly and inwardly relative to the cable drum. The cable feed device comprises a tubular housing through which the drain cleaning cable is to be fed. The tubular housing includes a pair of cable driving rollers fixedly mounted thereon such that the axis of each driving roller is skewed both horizontally and vertically relative to the central axis of the tubular housing. The tubular housing further includes a radially extending bore which receives a drive actuating roller support member having a drive actuating roller mounted on the inner end thereof. The support member supports the drive actuating roller in the tubular housing such that the axis of the drive actuating roller is skewed horizontally with respect to the axis of the tubular housing, preferably at the same angle as that of the driving rollers. The drive actuating roller support member is mounted so as to be biased outward from the tubular housing. A lever and handle are provided with the tubular housing for engaging and working against the outward biasing of the support member so as to move the support member and attached drive actuating roller within the tubular housing.
In operation, when the lever is in a disengaged position such that the support member is biased away from the central axis of the tubular housing, there is no axial displacement of the cable because the drive actuating roller is disengaged from the cable. When the handle of the lever is displaced downwardly, the support member is displaced radially inward against the cable to displace the cable against the drive rollers. As a result of the skewed position of the rollers, they interengage with the rotating cable to cause the cable to be fed in a direction relative to the tubular housing which depends on the direction of rotation of the cable, which in turns depends on the direction of rotation on the cable drum. Rotation of the cable in one direction advances it axially outward from the tubular housing, while rotation of the cable in the opposite direction draws the cable axially inward. When it is desired to stop the displacement of the cable in either direction, the handle is released and the drive actuating roller disengages the cable.
According to one embodiment described in Rutkowski, the cable feed device is mounted on the outer end of a flexible guide tube assembly affixed to the cable drum. While this embodiment allows a user to start and stop displacement of a cable at the work area, i.e., the opening to the drain, the direction of displacement of the cable can only be controlled by controlling the direction of rotation of the cable drum. Typically, the direction of rotation of the cable drum is controlled at the location of the cable drum itself, which in many applications is not within reach of the work area. Furthermore, when mounted at the end of a freestyle guide tube, the operations of the cable feed device is negatively impacted as the length and flex of the guide tube are increased. As length is increased, the friction of the rotating cable within the guide tube is also increased as a function of surface area in contact therebetween. This increase in friction is exacerbated by the distortion of the flexible guide tube during use. Irrespective of the length of the guide tube, the bending of the tube in use distorts the cross-sectional shape of the tube from circular to ellipsoidal and creates significant friction against and compression of the cable. As the cable is rotated within the tube, buildup of such frictional stresses can cause binding, kinking and looping of the cable within the tube, which deteriorates performance significantly.
Described is a drain cleaning apparatus having a remotely adjustable cable feed control. The drain cleaning apparatus includes a rotatable cable drum that carries a drain cleaning cable. Also included is a cable advancing mechanism mounted adjacent said drum having a housing that has an inner bore and a feed axis. The cable is adapted to pass from the cable drum and through the inner bore of the housing along the feed axis. The cable is also adapted to rotate about the feed axis when the cable drum is rotated. The cable advancing mechanism includes a plurality of rollers for engaging the cable. The rollers are selectively adjustable among a series of cable displacing positions preferably being a forward advancing position in which the cable, when rotating in a first direction, is fed out of the cable drum and along the feed axis and a reverse advancing position in which the cable, when also rotating in said first direction, is fed into the cable drum and along the feed axis. The rollers may also be placed in a neutral position in which the cable, when rotating in the first direction, is not fed along the feed axis. A conduit assembly is coupled to the cable advancing mechanism. The conduit assembly preferably includes an adjusting component and a guidecomponent, with the guide component preferably being located concentrically within the adjusting component. The guide component is adapted to receive the cable. The rollers may be selectively adjusted among the forward advancing, the reverse advancing and the neutral positions by rotating the adjusting conduit about its longitudinal axis by manual force. Additionally, a single component conduit may be utilized which maintains the flexibility and torsional strength characteristics to perform the functions set out herein. The rollers each have a rotational axis. In the neutral position, the rotational axes of the rollers are substantially parallel to the feed axis of the cable, and in the forward advancing and reverse advancing positions, the axes of the rollers are angled with respect to the feed axis of the cable. It is to be specifically noted that the operation of the feed control is continuous and infinitely adjustable from the neutral to the forward and reverse positions, allowing the user to select the speed of the cable throughput.
The conduit assembly may be removably yet rigidly attached to the cable advancing mechanism. Furthermore, each of the rollers may be rotatably supported by a carrier having a central axis wherein the carriers are mounted in the housing such that the central axes are substantially orthogonal to the feed axis and such that the carriers are rotatable about the central axes.
The cable advancing mechanism may include a cover plate rotatably affixed to the housing wherein the carriers that support the rollers are coupled to the cover plate such that rotation of the cover plate with respect to the housing causes the carriers to rotate about the central axes. In such a configuration, the neutral position corresponds to a first rotational position of the cover plate with respect to the housing and a first rotational position of the carriers, the forward advancing position corresponds to a second rotational position of the cover plate with respect to the housing and a second rotational position of the carriers, and the reverse advancing position corresponds to a third rotational position of the cover plate with respect to the housing and a third rotational position of the carriers. The conduit assembly may be attached to the cover plate such that the rotation of the adjusting conduit about its longitudinal axis simultaneously causes the cover plate to rotate with respect to the housing.
The housing may include a first indent and the cover plate may include a second indent wherein the first indent aligns with the second indent when the cover plate is positioned with respect to the housing so as to place the rollers in the neutral position. In this configuration, the drain cleaning apparatus includes a ball bearing and a spring inserted between the first and second indents when the first and second indents are aligned with one another. Additionally, it is to be understood that any device known to those skilled in the art may be substituted to identify the neutral position and temporarily restrain the rotation of the cover plate at that position.
These and other advantages and features of the present invention will be more fully understood with reference to the appended drawings and the description of the preferred embodiments.